Ventilation & Covid-19

When someone with COVID-19 breathes, speaks, coughs or sneezes, they release particles (droplets and aerosols) containing the virus that causes COVID-19. While larger droplets fall quickly to the ground, aerosols containing the virus can remain suspended in the air. If someone breathes in virus particles that are suspended in the air, they can become infected with COVID-19. This is known as airborne transmission.

In poorly ventilated rooms and workplaces the amount of virus in the air can build up, increasing the risk of spreading COVID-19, especially if there are lots of infected people in the room. The virus can also remain in the air after an infected person has left.
Bringing fresh air into a room and removing older stale air that contains virus particles reduces the chance of spreading COVID-19. The more fresh air that is brought inside, the quicker any airborne virus will be removed from the room1

The UK Government recommends that Ventilation should be considered alongside other control measures to reduce the risk of COVID-19 transmission within your workplace or public indoor space1.

Assessing the requirement and performance of ventilation systems in many environments requires engineering expertise. In addition, ventilation design may be specific to the setting. For some existing and older buildings, ventilation systems may not have been designed to meet current standards and additional mitigations may be needed.